Henry Kravis, founder and chairman of US buyout firm Kohlberg Kravis Roberts, said that his firm's listed vehicle had already started spending a $1.2bn (€935m) war chest for "opportunistic investments".

Kravis also said KKR Private Equity Investors, which is traded on pan-European exchange operator Euronext's Amsterdam bourse, had made a $195m investment in a "publicly-traded security", though he refused to provide any more details.